Readout integrated circuits involving pixel-level ADC for microbolometers

Readout integrated circuits involving a pixel-level analog-to-digital converter (ADC) are studied for 320 times 240 microbolometer focal plane arrays (FPAs). Each 2times2 pixel shares an readout circuit, including an operational amplifier(op-Amp), an integration capacitor and a single slope ADC. This readout circuit is designed to achieve 35 times 35 mum2 pixel size in 0.35 mum 2-poly 3-metal CMOS technology.